The present invention relates to a photosensitive media cartridge having an ambient condition sensor for sensing ambient conditions within the cartridge. The present invention further relates to an imaging arrangement in which imaging of photosensitive material within an imaging device is controlled based on ambient conditions within the cartridge.
Image forming devices which process a photosensitive media that includes microcapsules which encapsulate coloring material are known. In these imaging devices the microcapsules are exposed to a radiation based on image information. The microcapsules, whose mechanical strength can change when exposed to light, are ruptured by means of a crushing pressure, whereupon the coloring material and other substances encapsulated in the microcapsules flow out and development occurs. For example, some systems use a pair of upper and lower nip rollers to apply pressure. In these systems, the photosensitive media is passed between the pair of upper and lower nip rollers which apply pressure to the microcapsules to rupture the microcapsules and begin development. Imaging devices that employ microencapsulted photosensitive compositions are disclosed in U.S. Pat. Nos. 4,399,209, 4,416,966, 4,440,846, 4,766,050, 5,783,353, and 5,916,727.
A problem in processing photosensitive media having microencapsulated color forming material is that printing and/or imaging can be adversely affected by ambient conditions. That is, ambient conditions around a printer housing, around the photosensitive media, or in the cartridge which carries the photosensitive media can adversely affect subsequent printing or development of the image. More specifically, ambient conditions such as humidity around the printer housing, at the photosensitive media or in the cartridge which houses the photosensitive media can have adverse affects on the chemicals of the coloring material, the encapsulating material, and/or the photosensitive media. Further, the degree of hardening or curing of the microcapsules and the consequent increase in viscosity of the microcapsule varies with a change in humidity. As a result, photographic characteristics such as speed, minimum and maximum density, fogging density and full color imaging can be adversely affected.
The present invention provides for a media cartridge as well as an image forming device and method for processing photosensitive media that overcomes the above-mentioned drawbacks. More specifically, the present invention relates to an imaging device in which light sensitive media that contains light sensitive, rupturable microcapsules can be first exposed and then developed by applying pressure to the light sensitive media In the image forming device of the present invention, print image quality can be improved by sensing ambient conditions such as humidity in the printer, directly from the media, or in the cartridge which carries the media, and adjusting at least one adjustable parameter based on the sensed ambient condition. As an example, in response to a sensed humidity condition, a controller or development member of the present invention can accordingly adjust the amount of pressure applied to the microcapsules.
As indicated above, in the imaging device of the present invention, the photosensitive medium contains light sensitive, rupturable microcapsules that are exposed and then developed by the application of pressure using a stylus or pinch rollers to rupture unexposed microcapsules. Thereafter, the developed print is fixed with heat supplied by a heater in the imaging device. In the present invention, the level of relative humidity can be sensed inside and/or outside of the printer, in the media cartridge or directly on the photosensitive media, and then at least one of the parameters of light exposure, developing pressure, printing speed or fixing temperature can be adjusted automatically on the basis of the relative humidity level to provide an improved image. As an example, by adjusting the printing speed for a printer, the so called xe2x80x9cdark timexe2x80x9d which is the time between exposure and development will be changed. The dark time affects the hardness of microcapsules and therefore their crushability. Also, within the context of the present invention, the concept of sensing the level of relative humidity on the photosensitive media refers to sensing the moisture content on the photosensitive media or material.
The imaging device of the present invention also includes an improved pressure assembly for applying a uniform pressure to the photosensitive media.
The present invention relates to a photosensitive media cartridge which comprises a housing for holding a stack of photosensitive media; and an ambient condition sensor mounted within the housing for sensing ambient conditions in the housing and providing an ambient condition signal indicative thereof, wherein a development of the photosensitive media is based on the sensed ambient condition. The ambient condition signal can also be indicative of rh storage levels of the photosensitive media.
The present invention further relates to an image forming arrangement which comprises an image forming device for forming a latent image on a photosensitive medium, with the photosensitive medium comprising a plurality of microcapsules which encapsulate imaging material. The image forming device comprises a pressure assembly for applying an initial pressure to the photosensitive medium to crush the microcapsules and develop a latent image on the photosensitive medium. The arrangement further includes a media cartridge for holding a stack of the photosensitive medium therein, with the media cartridge being adapted to be inserted into the image forming device to permit a conveyance of the photosensitive medium to the image forming device. The media cartridge comprises an ambient condition sensor mounted within the cartridge for sensing ambient conditions within the cartridge and providing an ambient condition signal indicative thereof to the pressure assembly, such that an amount of pressure applied by the pressure assembly is based on the ambient conditions sensed by the ambient condition sensor in the cartridge.
The present invention further relates to a method of controlling image development which comprises the steps of: providing an ambient condition sensor in a cartridge which holds photosensitive media therein, with the ambient condition sensor sensing ambient conditions within the cartridge and providing an ambient condition signal indicative thereof to a development member of a printer; inserting the cartridge to an insertion position in the printer which permits a passage of photosensitive media from the cartridge to the development member in the printer; and controlling a development of images on the photosensitive media based on the ambient condition signal received from the ambient condition sensor mounted in the cartridge.